A coaxial cable is a transmission line, including an internal conductor, i.e., a core, and an external conductor, i.e., a shielding net, to surround the core while being spaced apart from the core. The core and the shielding net are insulated from each other by a flexible insulator that surrounds the core. The shielding net may be made of conductive metal threads. Alternatively, various other kinds of materials, such as a conductive tape, may be used. The conductive tape and the shielding net may overlap one another to minimize external interference.
Such a coaxial cable has been widely used in near field wired communication. In recent years, the coaxial cable has attracted considerable attention for communication in hybrid vehicles. When the coaxial cable is used in a vehicle, it is necessary for the coaxial cable to have a small sectional area, while having the above-described construction, so as to improve spatial utilization. In addition, it is necessary to manufacture a connector to interconnect a plurality of coaxial cables as small as possible.
Conventional coaxial cable connectors are disclosed in U.S. Pat. No. 6,840,822 and No. 6,736,653, both of which have been filed by the applicant of the present application, prior to the filing of the present application.
As shown in FIG. 9, U.S. Pat. No. 6,736,653 discloses a coaxial cable connector constructed to have a structure in which a dielectric sub assembly 14 to support a coaxial cable 16 is inserted into a plug housing 10 in the direction indicated by an arrow E, and an open type hatch 56 hingedly coupled to one side of the plug housing 10 is caught by a latch grip part 64 such that the dielectric sub assembly 14 is fixedly received in the plug housing 10.
Also, as shown in FIG. 10, the plug housing 10 may include a prong 120, and the dielectric sub assembly 14 may include a latch 140, such that the dielectric sub assembly 14 is fixed to the plug housing 10 by means of the prong 120 and the latch 140.
Specifically, the prong 120 extends toward a receiving end 24 from a bottom wall 36 of the plug housing 10 along guide beams 84 such that the prong 120 is separated from side walls 28 by slots 132. Also, a gap 136 is formed in the middle of the prong 120. Consequently, when the dielectric sub assembly 14 is inserted into the plug housing 10, the latch 140 is fitted into the gap 136 formed in the prong 120, thereby achieving coupling between the dielectric sub assembly 14 and the plug housing 10.
This double fixing structure to secure the dielectric sub assembly 14 to the plug housing 10 may be applied to secure the dielectric sub assembly 14 to a receptacle housing in the same manner.
Referring back to FIG. 9, a latch 40 extends from a coupling end 20 of the plug housing 10 such that the latch 40 can be elastically moved upward and downward. The latch 40 is fitted in a support strip (not shown) of the receptacle housing, thereby achieving the coupling between the plug housing and the receptacle housing.
Also, a latch beam 44 extends from the rear end of the latch 40 such that a user pushes the latch beam 44 to move the latch 40, with the result that the receptacle housing is separated from the plug housing.
In the connector structure disclosed in U.S. Pat. No. 6,736,653, however, support latches 60 coupled to the latch grip part 64 are easily opened to opposite sides thereof, with the result that coupling force between the open type hatch 56 and the latch grip part 64 may be reduced due to interference of components located in the vicinity of the connector.
On the other hand, the latch beam 44 is formed in the shape of a cantilever, with the result that the latch 40 may be lifted highly from the surface of the plug housing 10, and therefore, it is difficult to reduce the size of the connector. Also, when vibration generated during the driving of a vehicle is transmitted to the cantilever type latch 40, and therefore, the latch 40 accumulates fatigue, the latch 40 loses elasticity, with the result that the latch 40 may be separated from the receptacle housing.
Meanwhile, U.S. Pat. No. 6,840,822 discloses the structure of the previously described dielectric sub assembly. The dielectric sub assembly includes a contact connected to a core of a coaxial cable, a contact shell connected to a shielding net of the coaxial cable, and an insulation housing to fix the contact shell and the contact to the coaxial cable.
Referring to FIG. 11, a deformation restraint clamp 364, formed at the rear end of the contact shell 340, includes with arms 365 protruding from opposite lips 367 thereof. The contact shell 340 is positioned at the front end thereof, at which the contact shell 340 is connected to another contact shell in a contact manner, with arch tips 353 protruding from opposite walls 344 of the front end thereof.
Also, referring to FIG. 12, the insulation housing 400 includes a shell receiving slot 405 and channels 430. The arch tips 353 and the arms 365 are inserted into the shell receiving slot 405 and the channels 430, respectively. Subsequently, the portions of the arms 365 protruding from the opposite ends of the respective channels 430 are bent, with the result that the deformation restraint clamp 364 is securely fixed to the insulation housing 400.
The front and rear ends of the contact shell 340, fixed to the insulation housing 400, are separated from each other during the manufacture of the contact shell 340. For this reason, the front end of the contact shell 340 is fixed to the insulation housing 400 by coupling force generated when the arch tips 353 are inserted into the shell receiving slot 405, with the result that front end of the contact shell 340 has lower coupling force than the rear end of the contact shell 340, which is bent to be securely coupled to the insulation housing 400. Therefore, the front end of the contact shell 340 may be separated from the insulation housing 400 due to external impact during the transportation of the connector.
As shown in FIG. 13, on the other hand, a front end 500 of a plug contact shell and a front end 600 of a receptacle contact shell, which are coupled to each other by the connector, are formed approximately in the shape of having the same sectional size. The front end 500 of the plug contact shell and the front end 600 of the receptacle contact shell are coupled to each other in a sequential side-to-side coupling manner to define a shielding space T. Neighboring coaxial cables placed in the shielding space are connected to each other via their contacts.
When the front end 500 of the plug contact shell and the front end 600 of the receptacle contact shell are coupled to each other in the sequential side-to-side coupling manner, however, the connection between the respective contact shells may be deteriorated due to assembly defects.
That is, when the contact shells are coupled to each other while any one of the contact shells is displaced in one direction, signal contacts may be subjected to interference, especially when under vibration.